Infectious diseases are a major cause of morbidity, mortality and loss of economic productivity worldwide. Microbial drug resistance, emerging infections, use of microbes as bioterrorism weapons, and acquired immunodeficiency syndrome (AIDS) are examples of currently unsolved infectious disease problems. Developing improved methods to diagnose, treat and prevent infectious diseases and bioterrorism is a high national priority, and achieving that goal will require training additional scientists with expertise in microbial pathogenesis. This is the first competing renewal application for our postdoctoral training program on the Molecular Basis of Microbial Pathogenesis at the University of Colorado Health Sciences Center. Our training faculty currently consists of 18 highly interactive scientists from the Departments of Biochemistry and Molecular Genetics, Medicine, Microbiology, Neurology, Pediatrics and Pharmacology. They have outstanding NIH-funded research programs on microbial pathogenesis, documented success with postdoctoral-level training, extensive professional interactions, and excellent research facilities. Our program provides interdisciplinary, laboratory-based training on the molecular basis of microbial pathogenesis for basic biomedical scientists and physician-scientists. Our trainees supplement their laboratory research by taking advanced graduate-level courses in relevant basic biomedical sciences and scientific ethics, participating in a wide variety of seminars, journal clubs and data clubs, and attending national scientific meetings to present their research findings and interact with experts in their research areas. Major strengths of our program include the increasing size of our training faculty and the breadth of their interdisciplinary expertise, the increasing pool of eligible applicants and the high quality of the admitted trainees, the broad range of training activities, and the extensive interactions between our trainees and faculty members with Ph.D., M.D., and D.V.M. training. We will recruit actively for qualified trainees from under-represented minority groups. Most of our previous postdoctoral trainees are now successful research scientists in academia, government or the biotechnology/pharmaceutical industry.